How to calculate curb and gutter concrete?
Curb and gutter concrete in cubic yards (CY) is the cross-section area in square feet (SF) times the run length in linear feet (LF), divided by 27. Convert every section dimension from inches to feet first. A 1.75 SF section over 540 LF is 945 cubic feet, or 35 CY, before any allowance.
Curb and gutter concrete formula
- 1
Take the section dimensions from the curb and gutter detail, including curb depth below the pavement and pan thickness.
- 2
Split the section into rectangles that don’t overlap and convert each dimension to feet.
- 3
Multiply each rectangle’s width by its height and add the results for the section area in SF.
- 4
Multiply the area by the length in LF and divide by 27 for CY.
Curb and gutter concrete worked example
Take an example section, not a standard design: a curb 6 inches wide and 18 inches high with a gutter pan 24 inches wide and 6 inches thick beside it. Curb: 0.5 × 1.5 = 0.75 SF. Pan: 2.0 × 0.5 = 1.0 SF. Section area: 1.75 SF. Over 540 LF: 1.75 × 540 = 945 cubic feet, and 945 ÷ 27 = 35 CY. Per 100 LF, that is 175 ÷ 27 = 6.48 CY.
Curb and gutter sections that aren’t rectangles
A battered curb face, a sloped pan and rounded edges change the area. Break the shape into rectangles and triangles (half of base times height), or use the section area when the detail lists one. Keep driveway depressions and transitions as separate runs, and add any waste allowance after the volume, at the rate your own practice sets.